Unidirectional drive



April 5, 1932. A. CHOPIN UNIDIRECTIONAL DRIVE Filed Sept. 16, 1930 2 Sheets-Sheet 1 AYT R/Ve/J April 5, 1932. (:HQPIN 1,852,735

UNIDIRECTIONAL DRIVE Filed Sept. 16, 19:50 2 Shee,t -Sheet 2 I m1 1 V1 nn /0 v 9 w" x a M 1 I 4 j 1 62 //\/MEN7"O/Q /4 CHO p//\/ I y W W Patented Apr. 5, 1932 NITED STATES .ALBE'RIC GHOPIN, OF PARIS, FRAJSTCE UNIDIRECTIONAL' DRIVE Application filed September 16, 1930, Serial No. 482,312, and in France September 18, 1929. V

The present invention relates to unidirectional drives.

One of the objects of the invention is to provide means operative to establish a driving and driven relation between two rotatable elements, but only when the relative direction of rotation of said elements is a predetermined one.

Another object is to provide means operative to expand both radially and longitudinally to grip a casing of fixed dimensions when a shaft connected to said means is rotated in a predetermined direction.

Further objects will appear in the course of the detailed description now to be given with reference to the accompanying drawings, in which Fig. 1 is a phantom view, in perspective, of one illustrative embodiment of the invention;

Fig. 2 is a plan of the structure shown in Fig. 1;

Fig. 3 represents, in perspective, the central driving shaft of the assembly;

Fig. 4 shows a floating frictional element; and

Fig. 5 is a ing element.

Referring to the various figures of the drawings, there is shown a driving shaft 1 driven by a motor, pulley, or other suitable mechanism, (not shown) ,--a partially cylindrical block 2 suitably keyed to shaft 1 and including bosses 4 limited at one end by a surface 4 at right angles to the axis of shaft 1, at the other end by oblique plane surfaces, and laterally by a pair of convergent plane surfaces whose function will be pointed out further on,a driven shaft 5,a cylindrical casing rigidly attached to shaft 5 and limited laterally, by a cylindrical wall 6, and longitudinally by a pair of parallel transverse walls 6 and 6 ,a plurality of floating cylindrical segments or shoes 9 interposed between wall 6 and block 2, each shoe being limited by diverging lateral walls 10 and 11 having the same obliquity as the lateral portions of bosses 4,--and floating wedges 14 50 provided with one end surface 14 adapted to coact with surface 6 a second end-surface perspective of a detached Wedg- 14, parallel to, and adapted to slide on one end of a boss 4, and convergent lateral surfaces having the'same obliquity as surfaces 10 and 11. The hereinabove described tions as follows:

Assuming shaft 1' to be driven in the direction of arrow 7' (Fig. 1), the end oblique surface of each boss 4 will exert pressure on corresponding face 14 of each wedge 14 and force the latterin the direction of arrow f- (Figs. land 2) however,because of the obliquity of lateral surfaces 10 and 11 of shoes assembly func- 9, the latter will move radially outward and come into contact with internal cylindrical surface 6; at the same time, while correspond ing ends of each'shoe 9 move into forcible contact withsurface.6 surface 4 is thrust in theopposite direction into frictional contact with surface 6 bosses 4, shoes 9 and wedges 14 thus coact'to, simultaneously effect a locking action in both radial and longitudinal directions which insures very efficient coupling of shafts 1 and 5. When shaft 1 turns in the opposite direction, an inverse series of displacements occur and shafts l and 5 are completely uncoupled.

The use of a plurality of bosses, wedges and shoes permits easier centering of the assembly and their number may be varied at will.

The invention is particularly applicable to pneumatic hammers, to self-startersfor automobile motors, elevators, aeroplanes, etc.

In French Patent No. 652,184, having dlivr date October 22, 1928, to the same inven tor, an apparatus was described for obtaining a unidirectional drive by means of a cam element exerting radial pressure only on a plura-lityoffioatingshoes. Thepresentinvention is an improvement on this prior device in that the radial effect is supplemented by a longitudinal locking action, thus increasing the total area of the frictional surfaces in contact and at the same time insuring a more perfect coupling of the driving and driven shafts.

What I claim is: 1. In combination, adriving shaft, a drivon shaft, a casing having an internal cylindrical wall and an end wall, said casing being rigidly attached to said driven shaft, a plurality of floating shoes interposed between the walls of said casing and the driving shaft,

and a wedge mounted in driven relation to the driving shaft, said wedge being operative by the latter to force said shoes radially and longitudinally into contact with the-internal.- cylindricalhwall and an endiwall of saidr-casr; mg.

19 2. In combination, a driving shaft, a driven shaft, a casing having an 'interna'l-cylin drical wall and an end wall, said casing being v rigidly attached to the driven shaft,"means including; abosslconnected. insdriven relation 15 to the driving shaft, said boss having an oblique :surface ,7 formed: thereon-1 forming: an angle with a plane-:at :rightranglesto the" axis of the driving shaft, a .plurality'of' floating; .1 shoes interposed between said casings-andx the =dPlVTlI1g shaft, :said shoes havinggconvergent lateral surfaces, and a WQClgBQ-QhEL-VlTIgIfCOH-i vergent: lateral; surfaces: and :anzoblitlueeend surfaoe positioned :to contact with the c0rre-,: sponding oblique. surface of 7 said boss, .Sl'ldz;

wedge. being; positioned between said. =.shoes and adjacent amendlwall .of zsaid .-,casing,i: whereby-rotation of: said drivingsshaft :will 1 cause the oblique surfaces :of the wedge-and bossJto slide over one vanother and. bring ,the

convergent lateral surfaces Ofitlle'l'Wedge and. shoesinjcontanti so as do: force;the lateral 1 sur r-; F- faces'radially andlongitudinally intonconei tactrwithithe internalv-wallsof; thex casingn".

M Inutesftmrony whereof: I :have :signed (this i a specifi'cationaz:

ALBERIG? enormi- 

